Ubiquitin-like Proteins and Proteasomes of Archaea

古细菌的泛素样蛋白和蛋白酶体

基本信息

批准号：
8887421
负责人：
JULIE A MAUPIN-FURLOW
金额：
$ 24.77万
依托单位：
UNIVERSITY OF FLORIDA
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-04-01 至 2019-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8887421
关键词：
26S proteasome ATP phosphohydrolase Active Sites Affinity Archaea Binding Binding Proteins Biochemical Biological Biology Biotechnology Cell division Cell physiology Cells Coiled-Coil Domain Complex DNA Repair Degradation Pathway Development Enzymes Eukaryota Eukaryotic Cell Evolution Florida Genetic Transcription Growth Haloferax volcanii Health High temperature of physical object Homologous Gene Human Human papillomavirus 16 E1 protein Knowledge Laboratories Life Ligase Link Longevity Lysine Malignant Neoplasms Mantle Cell Lymphoma Measures Mediating Metabolism Metalloproteases Modeling Modification Molecular Multiple Myeloma N-terminal Names Nerve Degeneration Oxidative Stress Oxygen Pathogenesis Pathway interactions Patients Peptide Hydrolases Pharmaceutical Preparations Plant Roots Post-Translational Protein Processing Property Proteasome Inhibitor Protein Binding Proteins Proteolysis Public Health Refractory Regulation Relapse Research Resistance Respiration Ribonucleases Role Site Stress Structure Sulfur System Tertiary Protein Structure Thiouridine Transfer RNA Translations Tuberculosis Ubiquitin Ubiquitin Like Proteins Universities Variant Virus Diseases amino group biological adaptation to stress chemotherapy design enzyme activity grasp hypercholesterolemia inhibitor/antagonist insight methionine sulfoxide reductase molybdenum cofactor multicatalytic endopeptidase complex mutant news overexpression oxidation pathogen protein protein interaction public health relevance skills stoichiometry thermal stress

项目摘要

DESCRIPTION (provided by applicant): Ubiquitin-proteasome systems and their homologs are attractive targets for the treatment of some of the most formidable public health challenges of this century including cancer, viral infections, tuberculosis, hypercholesteremia and neurodegeneration. Promising news is that use of proteasome inhibitors, in combination with immunomodulatory drugs, has greatly extended the lifespan of patients with relapsed/refractory multiple myeloma. The fundamental knowledge that enabled the development of these inhibitors was spearheaded by structure-function studies of proteasomes from Archaea. Recently, we discovered that Archaea synthesize ubiquitin-like proteins named SAMPs that are attached by isopeptide bonds to lysine residues of target proteins by an E1-like mechanism (sampylation) that resembles ubiquitylation. SAMPs also mobilize sulfur to form thiolated tRNA and molybdopterin. We hypothesize that SAMPs provide a window for understanding how ubiquitin-like proteins evolved to control cell function including the transient inactivation of enzyme function, targeting of proteins for destruction by proteasomes and coordination of protein modification with sulfur mobilization pathways associated with stress responses. In our research, we demonstrate that polymeric chains of SAMPs are attached near the conserved active site residues of thiouridine synthetase (NcsA), an enzyme linked to oxidative and thermal stress and associated with ubiquitin- like proteins in all domains of life. We also find that many of the lysine residues modified by `sampylation' are near catalytic active sites suggesting a general mechanism of transient enzyme inactivation that may be conserved in eukaryotic cells. SAMPs are also found to target proteins for destruction by mechanisms that appear to require N-terminal degrons and 26S proteasome components. Here we will use the halophilic archaeon Haloferax volcanii as a model to provide insight into how ancient ubiquitin-like modification pathways may control biological activity. In Aim 1, we will define and determine the biological role of the formation of polymeric ubiquitin-like chains of SAMP2 on the thiouridine synthetase (NcsA) associated with maintaining translation fidelity and overcoming thermal stress. In Aim 2, we will provide mechanistic insight into SAMP attachment at or near catalytic active site residues to infer general principles of enzyme regulation that may extend across domains of life. In Aim 3, we will define the interactions of the SAMPs with proteasome-associated AAA ATPases and JAMM/MPN+ domain proteins that may be conserved through evolution. At the conclusion of these studies, we will have expanded our knowledge of ubiquitin-like protein modification and provided an evolutionary perspective on how these attachments may regulate enzyme activity, proteolysis and association with protein partners including proteasomes.

描述（由申请人提供）：泛素蛋白酶体系统及其同源物是治疗本世纪一些最严峻的公共卫生挑战的有吸引力的靶标，这些挑战包括癌症、病毒感染、结核病、高胆固醇血症和神经变性。蛋白酶体抑制剂与免疫调节药物联合使用，大大延长了复发/难治性多发性骨髓瘤患者的寿命。最近，我们发现古细菌合成了名为 SAMP 的类泛素蛋白，这些蛋白通过类似 E1 的机制通过异肽键连接到目标蛋白的赖氨酸残基上。 sampylation）类似于泛素化，也可以动员硫形成硫醇化 tRNA 和钼蝶呤。 SAMP 为了解泛素样进化蛋白质如何控制细胞功能提供了一个窗口，包括酶功能的瞬时失活、蛋白酶体破坏的蛋白质以及蛋白质修饰与应激反应相关的硫动员途径的协调。证明 SAMP 的聚合链附着在硫尿苷合成酶 (NcsA) 的保守活性位点残基附近，硫尿苷合成酶是一种与氧化和热应激相关的酶，并与我们还发现，许多通过“sampylation”修饰的赖氨酸残基都位于催化活性位点附近，这表明在瞬时 SAMP 中也存在保守的酶失活的一般机制。通过似乎需要 N 末端降解决定子和 26S 蛋白酶体成分的机制来破坏目标蛋白质在这里，我们将使用嗜盐古菌 Haloferax。 volcanii 作为模型，深入了解古代泛素样修饰途径如何控制生物活性。在目标 1 中，我们将定义并确定 SAMP2 聚合泛素样链形成对硫尿苷合成酶 (NcsA) 的生物学作用。在目标 2 中，我们将提供对催化活性位点残基处或附近的 SAMP 附着的机制见解，以推断一般原理。在目标 3 中，我们将定义 SAMP 与蛋白酶体相关的 AAA ATP 酶和可能在进化过程中保守的 JAMM/MPN+ 结构域蛋白的相互作用。将扩展我们对类泛素蛋白质修饰的了解，并提供关于这些附件如何调节酶活性、蛋白水解以及与包括蛋白酶体在内的蛋白质伙伴的关联的进化视角。